Hypodermic needle assembly

ABSTRACT

A needle assembly especially suited for hypodermic syringe use in which an axially collapsible sleeve is positioned over the needle. The sleeve includes an upper axially rigid portion sized to mount over the base portion of the needle, an axially collapsible intermediate portion, and an axially rigid lower portion defining a central bore sized to telescopically receive and protect the lower pointed end of the needle. In use, the sleeve selectively collapses axially as the needle enters the subject so that the point of the needle is never exposed during insertion, and selectively extends axially during withdrawal of the needle so that again the pointed tip of the needle is never exposed.

This is a continuation of application Ser. No. 170,680 filed on Mar. 16,1988 now abandoned which was a continuation of Ser. No. 033,657 filed onApr. 3, 1987 now abandoned.

BACKGROUND OF THE INVENTION

This invention relates to hypodermic needle assemblies of the typesuitable for receiving and dispensing medication.

Various types of needle assemblies are known for receiving anddispensing medication. The needle assemblies are typically utilized witha syringe device including a hollow barrel and a plunger positionedwithin the barrel and operative in response to upward and downwardmovement of the plunger within the barrel to dispense fluid through thehollow shaft portion of the needle or withdraw fluid upwardly into thebarrel through the hollow shaft portion of the needle. The lower end ofthe shaft portion of the needle is of necessity sharply pointed and assuch presents a hazard whenever the point is exposed. Needle assembliestypically include a sheath which is cup shaped and which fitstelescopically over the shaft portion of the needle with the upper endof the sheath suitably mounted on the base portion of the needle. Inposition, the cup shaped sheath totally shields the pointed end of theneedle and prevents injury to users of the needle. Prior to use of theneedle assembly, the shield is removed from the needle and the needle isutilized in known manner to either dispense medication or receive fluid.The sharp point of the needle is therefore exposed at all timesfollowing removal of the safety sheath until the needle assembly isultimately disposed of, and it is not at all uncommon for puncturewounds to be inflicted by the exposed sharp point of the needle duringthe time between removal of the sheath and ultimate disposal of theneedle assembly. Various devices have been proposed in the past to serveas a shield to protect the needle during and after use but these deviceshave either been ineffective in terms of performing their shieldingfunction or have been unduly complicated with respect to theirconstruction or their use. In any event, none of these needle shielddevices have achieved any significant degree of commercial acceptancebecause of their ineffectiveness and/or complexity.

SUMMARY OF THE INVENTION

This invention is directed to the provision of a needle assembly inwhich the sharp point of the needle is protected at all times during andafter use of the needle assembly.

The needle assembly of the invention includes an injection needleincluding a relatively large diameter hollow base portion and arelatively small diameter hollow shaft portion extending downwardly fromthe base portion and including a lower end portion terminating in apointed tip; and an elongated unitary sleeve sized to fit telescopicallyover the needle and including an axially rigid upper mounting portionsized to mount over the needle base portion, an axially collapsibleintermediate portion, and an axially rigid lower portion defining anaxially extending central bore sized to telescopically receive theneedle lower end portion and positioned, with the upper sleeve portionmounted over the needle base portion and the intermediate sleeve portionaxially extended, in surrounding relation to the needle end portion withthe pointed tip spaced upwardly from the lower end of the bore. Withthis arrangement, the needle is constantly protected by the sleeve andyet the sleeve yields axially in response to insertion of the needleinto the patient or into a suitable aperture to allow the needle toenter the patient without the pointed tip of the needle ever beingexposed.

According to a further feature of the invention, the sleeve has agenerally uniform diameter throughout its length and the central boredefined in the lower rigid portion the sleeve has a diameter less thanthe diameter of the needle base portion and greater than the diameter ofthe needle shaft portion. This arrangement allows the lower end portionof the needle shaft to be positioned telescopically within the centralbore of the lower end portion of the sleeve and allows the sleeve toguide on the needle shaft portion as it collapses axially in response toinsertion of the needle into an appropriate subject.

In one embodiment of the invention, the needle base portion isexternally threaded and the upper mounting portion of the sleeve isinternally threaded for threaded coaction with the externally threadedneedle base portion. In another embodiment of the invention, the uppermounting portion of the sleeve is sized to be press fit over the needlebase portion. In either arrangement, the upper end of the sleeve isconveniently and positively secured to the needle base portion topreclude inadvertant relative movement as between the sleeve and theneedle.

According to a further feature of the invention the sleeve has agenerally uniform external diameter throughout its length; the uppersleeve portion has an internal diameter approximating the externaldiameter of the needle base portion; the intermediate sleeve portion ispleated; and the lower sleeve portion has a thickened annular wall andthe central bore has a diameter less than the diameter of the needlebase portion and greater than the diameter of the needle shaft portion.This specific construction of the sleeve allows the sleeve to fitreadily and securely over the needle base portion; allows theintermediate portion of the sleeve to readily collapse to accommodateentry of the needle into a subject; and provides a convenient means ofdefining the central bore in a sleeve of generally uniform externaldiameter.

According to a further feature of the invention, the assembly furtherincludes an elongated cup shaped sheath fitted telescopically over thesleeve with its closed lower end positioned intermediately beneath thelower end of the sleeve lower portion and its open upper end positionedconcentrically around the needle base portion and the sleeve upperportion. This arrangement allows the sheath of the prior art to beutilized with the sleeve shield of the invention so that the sheath mayprotect the entire assembly during shipment and storage and the sleevemay protect the pointed tip of the needle following removal of thesheath.

According to a further feature of the invention, the needle assemblyfurther includes a syringe including a hollow cylindrical barrel open atits upper end and secured at its lower end to the needle base portionand a plunger extending into the open upper end of the barrel andincluding a piston at its lower end for sealing coaction with the barrelto move liquid downwardly from the barrel and downwardly through theneedle in response to downward movement of the plunger and move liquidupwardly through the needle and into the barrel in response to upwardmovement of the plunger. This arrangement allows the invention sleeveshield to be utilized in a typical hypodermic syringe assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal cross sectional view of the needle assemblyaccording to the invention;

FIG. 2 is a view of a sleeve for use in the invention needle assembly;

FIG. 3 is an exploded view of the needle assembly of FIG. 1;

FIG. 4 is a longitudinal cross sectional view of the invention needleassembly utilized in a hypodermic syringe assembly; and

FIG. 5 is a fragmentary view of the needle assembly of FIG. 3 with asheath covering the shaft 14 of the needle.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The needle assembly seen in FIGS. 1 and 3 includes a needle 10, a sleeve12, a sheath 14, and a cap 16. Sleeve 12, sheath 14, and cap 16 may beformed of a suitable plastic material in an injection molding process.Needle 10 may be of all metallic construction or may be of a compositeplastic and metal construction.

Needle 10 includes a relatively large diameter hollow base portion 10aand a relatively small diameter hollow shaft portion 10b extendingdownwardly from the base portion and including a lower end portion 10cterminating in a pointed tip 10d. Base portion 10a is preferably formedof a plastic material and includes an upper annular lip 10e and externalthreads 10f. Needle shaft portion 10b is preferably formed of a suitablemetallic material and is secured in known manner to the lower end ofbase portion 10a.

Sleeve 12 is formed as an injection molded unitary plastic member in asize to fit telescopically over needle 10. Sleeve 12 includes an axiallyrigid upper mounting portion 12a sized to mount over needle base portion10a, an axially collapsible intermediate portion 12b, and an axiallyrigid lower portion 12c defining an axially extending central bore 12dsized to telescopically receive the needle lower end portion 10c andpositioned, with upper portion 12a mounted on needle base portion 10aand intermediate portion 12b axially extended, in surrounding relationto needle end portion 10c with the needle pointed tip 10d spacedupwardly from the lower end of bore 12d.

An annular lip 12e is formed at the upper end of upper mounting portion12a and internal threads 12f are provided in upper portion 12a forthreaded coaction with the threads 10f on needle base portion 10a.Intermediate portion 12b is constituted by a series of integral pleats12g. Pleats 12g have an axially extended normal position, as seen inFIG. 1 in which the individual pleats are axially spaced to provide asleeve length in which the tip 10d of the needle is positioned withinbore 12d of the sleeve in spaced relation to the lower end of thesleeve, and a collapsed position, as seen in FIG. 2, in which the sleevelength is foreshortened by the extent of collapsing axial movement ofthe intermediate portion to allow selective exposure of the pointed tipof the needle.

The lower sleeve portion 12c has a thickened annular wall 12h definingthe central bore 12d and the central bore 12d has a diameter slightlygreater than the diameter of needle shaft portion 10b so as to readilyslidably receive the shaft portion 10b. Bore 12d fits closely enougharound shaft portion 10b so that shaft portion 10b serves as a centralguide for the collapsing movement of the sleeve.

Sheath 14 is generally cup shaped and includes a main body cylindricalwall portion 14a, a solid lower end wall 14b, an open upper end 14c, andan annular bead or lip 14d spaced downwardly from open end 14c to definean upper end portion 14e. Sheath 14 is sized to fit telescopically oversleeve 12 and has a length generally corresponding to the length ofsleeve 12.

Cap 16 is cup shaped and is sized to fit telescopically over upper endportion 14e of sheath 14.

In assembled relation, as seen in FIG. 1, sleeve 12 is telescopicallyreceived over needle 10 with sleeve upper portion 12a threaded ontoneedle base portion 10a, sleeve lower end portion 12c telescopicallyreceiving and circumferentially surrounding needle lower end portion10c, and needle tip 10d spaced upwardly from the lower end of sleevebore 12d; sheath 14 is telescopically received over sleeve 12 with theopen upper end 14c of the sheath seating against lip 12e on the upperend of the sleeve and with wall 14b positioned immediately beneath thelower end of sleeve bore 12d; and cap 16 is fitted over the upper endportion 14e of sheath 14 in seating engagement with sheath bead 14d.

The invention needle assembly may be supplied in the form seen in FIG. 1or, alternatively, may be provided as part of a hypodermic syringeassembly as seen in FIGS. 4 and 5.

The hypodermic syringe assembly of FIGS. 4 and 5 includes a needle 10, asleeve 12, a sheath 14, and a syringe 18.

Syringe 18 includes a hollow cylindrical barrel 20 and a plunger 22.

Barrel 20 is open at its upper end 20a and includes a hollow mountinghub portion 20b at its lower end.

Plunger 22 is slidably received in barrel 20 and includes a piston 22afor sealing coaction with the inner cylindrical wall of the barrel asthe plunger is moved up and down in known manner within the barrel.

The assembly of FIGS. 4 and 5 does not include a cap 16 but, rather, theupper end or base portion 10a of the needle is mounted directly and inknown manner in the base portion 20b of the barrel 20 of the syringe.The upper end of sleeve 12 is threaded into abutting engagement with thelower end of barrel hub portion 20b. In the assembled relation as seenin FIG. 4, continuous passage is established from the interior of barrel20 downwardly through a central bore 20c in the hub portion 20b of thebarrel and then downwardly through the hollow needle.

If syringe assembly 18 and a needle assembly of the type seen in FIG. 1are provided as separate entities, the hypodermic needle assembly isprepared for use by removing the cap 16, inserting the upper end of theneedle base portion 10a into barrel hub portion 20b to secure the needletherein in known manner, and removing sheath 14. If the assembly isprovided in the form seen in FIG. 4 with the syringe already mounted tothe needle, the assembly is prepared for use simply by removing thesheath 14.

In either situation, as pressure is thereafter exerted downwardly on thesyringe with the lower end of sleeve 12 positioned against the subject24 to be treated, the intermediate portion 12b of the sleeve selectivelycollapses axially as the pointed tip of the needle shaft enters thesubject to selectively expose the needle. As the needle is thereafterwithdrawn, following either injection of a fluid into the subject orwithdrawal of a fluid from the subject, the sleeve 12 selectivelyexpands axially to selectively cover the needle tip as it emerges fromthe subject so that, the needle tip is never exposed in either theneedle entry or needle withdrawal operations. Since most hypodermicassemblies are now of the one use, disposable type, the entire assemblywould thereafter immediately be disposed of with the axially extendedsleeve continuing to protect the exposed tip of the needle during thedisposal process so as to continue to guard against inadvertant injurycaused by the exposed needle.

As seen in FIG. 2, the upper rigid portion 12a of sleeve 12 may beprovided with a smooth bore, rather than a threaded internal bore, andthe upper portion 12a may be press fit on the upper end 10a of needle10, in which case the external thread 10f on the upper portion 10a ofthe needle would be omitted to provide a proper press or interferencefit as between the upper end of the sleeve and the needle base portion.

The invention will be seen to provide a hypodermic needle assembly inwhich the point of the needle is protected at all times during and afteruse to avoid injury caused by the exposed point of the needle. Theprotective sleeve of the invention is extremely effective in preventinginjury from the tip of the needle and yet may be readily andinexpensively manufactured at a cost consistent with the extremely lowcost of modern day disposable needle assemblies. In fact, the inventionsleeve only insignificantly increases the overall cost of the needleassembly as compared to needle assemblies in which no such protection isprovided.

Whereas preferred forms of the invention have been illustrated anddescribed in detail, it will be apparent that various changes may bemade in the disclosed embodiments without departing from the scope orspirit of the invention.

I claim:
 1. A needle assembly comprising:(a) an injection needleincluding a relatively large diameter hollow base portion and arelatively small diameter hollow shaft portion extending downwardly fromsaid base portion and including a lower end portion terminating in apointed tip; and (b) an elongated unitary sleeve sized to fittelescopically over said needle and including an axially and radiallyrigid upper mounting portion sized to mount over said needle baseportion and including means for coaction with said base portion todetachably secure said sleeve to said base portion, an axiallycollapsible intermediate portion formed integrally with said uppermounting portion and having a normal extended condition and a collapsedcondition to respectively provide a relatively long and a relativelyshort overall length for said sleeve, and an axially and radially rigidlower portion formed integrally with said intermediate portion anddefining an axially extending central bore, of constant length anddiameter irrespective of the extended or collapsed condition of saidintermediate portion, opening to the atmosphere centrally in the lowerend of said sleeve and sized to telescopically but loosely slidablyreceive said needle lower end portion and positioned, with said uppersleeve portion mounted over said needle base portion and saidintermediate portion in its axially extended condition, in surroundingrelation to said needle end portion with said pointed tip spacedupwardly from the open lower end of said bore.
 2. A needle assemblyaccording to claim 1 wherein:(c) said sleeve has a generally uniformdiameter throughout its length; and (d) said central bore has a diameterless than the diameter of said needle base portion and greater than thediameter of said needle shaft portion.
 3. A needle assembly according toclaim 1 wherein:(c) said needle base portion is externally threaded; and(d) said upper mounting portion of said sleeve is internally threadedfor threaded coaction with said externally threaded needle base portionto detachably secure said sleeve to said needle base portion.
 4. Aneedle assembly according to claim 1 wherein:(c) said upper mountingportion of said sleeve is sized to be press fit over said needle baseportion to detachably secure said sleeve to said needle base portion. 5.A needle assembly according to claim 1 wherein:(c) said sleeve is formedas an injection molded unitary plastic member and has a generallyuniform external diameter throughout its length; (d) said upper sleeveportion has an internal diameter approximating the external diameter ofsaid needle base portion; (e) said intermediate sleeve portion ispleated; and (f) said lower sleeve portion has a thickened annular walland said central bore has a diameter less than the diameter of saidneedle base portion and greater than the diameter of said needle shaftportion.
 6. A needle assembly comprising:(a) an injection needleincluding a relatively large diameter hollow base portion and arelatively small diameter hollow shaft portion extending downwardly fromsaid base portion and including a lower end portion terminating in apointed tip; (b) and elongated unitary sleeve sized to fittelescopically over said needle and including an axially and radiallyrigid upper mounting portion sized to fit over said needle base portionand including means for coaction with said needle base portion, todetachably secure said leeve to said needle base portion, an axiallycollapsible intermediate portion formed integrally with said uppermounting portion and having a normal extended condition and an collapsedcondition to respectively provide a relatively long and a relativelyshort overall length for said sleeve, and an axially and radially rigidlower portion formed integrally with said intermediate portion anddefining an axially extending central bore, of constant length anddiameter irrespective of the extended or collapsed condition of saidintermediate portion, opening to the atmosphere centrally in the lowerend of said sleeve and sized to telescopically but loosely slidablyreceive said needle lower end portion and positioned, with said upperportion mounted over said needle base portion and said intermediateportion in its axially extended condition, in surrounding relation tosaid needle lower end portion with said pointed tip spaced upwardly fromthe open lower end of said bore; and (c) an elongated cup shaped sheathfitted telescopically over said sleeve and having an imperforate, closedlower end positioned immediately beneath the lower end of said sleevelower portion and an open upper end positioned concentrically aroundsaid needle base portion and said sleeve upper portion.
 7. A needleassembly according to claim 6 wherein:(d) said sleeve has a generallyuniform diameter throughout its length; and (e) said central bore has adiameter less than the diameter of said needle base portion and greaterthan the diameter of said needle shaft portion.
 8. A needle assemblyaccording to claim 7 wherein:(e) said needle base portion is externallythreaded; and (f) said upper mounting portion of said sleeve isinternally threaded for threaded coaction with said externally threadedneedle base portion to detachably secure said sleeve to said needle baseportion.
 9. A needle according to claim 7 wherein:(e) said uppermounting portion of said sleeve is sized to be press fit over saidneedle base portion to detachably secure said sleeve to said needle baseportion.
 10. A needle assembly according to claim 6 wherein:(d) saidsleeve has a generally uniform external diameter throughout its length;(e) said upper sleeve portion has an internal diameter approximating theexternal diameter of said needle base portion; and (f) said lower sleeveportion has a thickened annular wall and said central bore has adiameter less than the diameter of said needle base portion and greaterthan the diameter of said needle shaft portion.
 11. A needle assemblycomprising:(a) an injection needle including a relatively large diameterhollow base portion and a relatively small diameter hollow shaft portionextending downwardly from said base portion and including a lower endportion terminating in a pointed tip; (b) an elongated unitary sleevesized to fit telescopically over said needle and including an axiallyand radially rigid upper mounting portion sized to fit over said needlebase portion and including means for coaction with said needle baseportion to detachably secure said sleeve to said needle base portion, anaxially collapsible intermediate portion formed integrally with saidupper mounting portion and having a normal extended condition and acollapsed condition to respectively provide a relatively long andrelatively short overall length for said sleeve, and an axially andradially rigid lower portion formed integrally with said intermediateportion and defining an axially extending central bore, of constantlength and diameter irrespective of the extended or collapsed conditionof said intermediate portion opening to the atmosphere centrally in thelower end of said sleeve and sized to telescopically but looselyslidably receive said needle lower end portion and positioned, with saidupper portion mounted over said needle base portion and saidintermediate portion in its axially extended condition, in surroundingrelation to said needle lower end portion with said pointed tip spacedupwardly from the open lower end of said bore; (c) an elongated cupshaped sheath fitted telescopically over said sleeve and having animperforate, closed lower end positioned immediately beneath the lowerend of said sleeve lower portion and an open upper end positionedconcentrically around said needle base portion and said sleeve upperportion; and (d) a syringe including a hollow cylindrical barrel open atits upper end and secured at its lower end to said needle base portionand a plunger extending into the open upper end of said barrel andincluding a piston at its lower end for sealing coaction with saidbarrel to move liquid downwardly from said barrel and downwardly throughsaid needle in response to downward movement of said plunger and movefluid upwardly through said needle into said barrel in response toupward movement of said plunger.
 12. A needle assembly according toclaim 11 wherein:(e) said sleeve has a generally uniform diameterthroughout its length; and (f) said central bore has a diameter lessthan the diameter of said needle base portion and greater than thediameter of said needle shaft portion.
 13. A needle assembly accordingto claim 11 wherein:(e) said needle base portion is externally threaded;and (f) said upper mounting portion of said sleeve is internallythreaded for threaded coaction with said externally threaded needle baseportion to detachably secure said sleeve to said needle base portion.14. A needle assembly according to claim 11 wherein:(e) said upperportion of said sleeve is sized to be press fit over said needle baseportion to detachably secure said sleeve to said needle base portion.15. A needle assembly according to claim 11 wherein:(e) said sleeve hasa generally uniform external diameter throughout its length; (f) saidupper sleeve portion has an internal diameter approximating the externaldiameter of said needle base portion; (g) said intermediate sleeveportion is pleated; and (h) said lower sleeve portion has a thickenedannular wall and said central bore has a diameter less than the diameterof said needle base portion and greater than the diameter of said needleshaft portion.
 16. A needle assembly according to claim 6 and furtherincluding:(d) a cup shaped cap fitted telescopically over the upper endportion of said sheath and concentrically around said needle baseportion and said sleeve upper portion.
 17. A needle assemblycomprising:(A) an injection needle including a relatively large diameterhollow upper portion, having an open upper end, and a relatively smalldiameter hollow shaft portion extending downwardly from said upperportion and including an lower end portion terminating in a pointed tip;(B) an elongated unitary sleeve sized to fit telescopically over saidneedle and including a rigid upper mounting portion sized to mount oversaid needle upper portion and including means for coaction with saidupper portion to detachably secure said sleeve to said upper portion, anaxially collapsible intermediate portion formed integrally with saidupper mounting portion and having a normal extended condition and acollapsed condition to selectively provide a relatively long and arelatively short overall length for said sleeve, and a rigid lowerportion formed integrally with said intermediate portion and defining anaxially extending central bore opening to the atmosphere centrally inthe lower end of said sleeve and sized to telescopically receive saidneedle lower end portion and positioned, with said upper sleeve portionmounted over said needle upper portion and said intermediate portion inits axially extended condition, in surrounding relation to said needleend portion with said pointed tip spaced upwardly from the open lowerend of said bore; and (c) sealing means including a seal member separatefrom said sleeve member and said needle member, including a portionextending beneath said sleeve member lower portion in underlying butunattached relation to the lower end of said sleeve, coacting with atleast one of said sleeve and needle members to preclude the entry ofcontaminants into the open lower end of said bore, and readily removablyfrom said sleeve member and said needle member to allow said pointed tipto pass freely through the open lower end of said bore.
 18. A needleassembly according to claim 17 wherein said sealing means furtherincludes means overlying the open upper end of said needle member upperportion and coacting with at least one of said members to preclude theentry of contaminants into the open upper end of said upper portion ofsaid needle member.
 19. A seal assembly according to claim 17 whereinsaid seal member comprises a tubular member received telescopically oversaid sleeve member, detachably secured at its upper end to said sleevemember upper portion, and including an imperforate lower end wallunderlying said open lower end of said bore.
 20. A needle assemblyaccording to claim 19 wherein said sealing means includes a furthersealing member positioned in overlying relation to the open upper end ofsaid needle member upper portion, detachably secured to at least one ofsaid members, and coacting with at least one of said members to precludethe entry of contaminants into the open upper end of said needle memberupper portion.
 21. A needle assembly according to claim 20 wherein saidfurther sealing member comprises a tubular member receivedtelescopically over said upper portion of said needle member, detachablysecured at its lower end to one of said members, and including animperforate upper end wall overlying the open upper end of said needlemember upper portion.